(i) Technical Field
The present invention relates to a method for fabricating a semiconductor device.
(ii) Related Art
There is a case where a semiconductor device such as a FET (Field Effect Transistor) like a HEMT (High Electron Mobility Transistor) using a nitride semiconductor such as GaN (gallium nitride) is used as an output amplifier for high frequency. Japanese Patent Application Publication No. 2009-200306 (hereinafter referred to as Document 1) discloses an invention of forming SiN (silicon nitride) layers having different refractive index and removing impurity on a surface of a semiconductor layer.